To gain percutaneous access into the intrapericardial space (i.e., the space between the pericardial sac and the heart wall), doctors use a sub-xiphoid puncture technique employing a 17-gauge Touhy needle. Doctors use fluoroscopic guidance to visualize the needle placement with respect to the heart. Contrast media is also used during puncture to determine if the needle has passed through the pericardial sac and is correctly located in the intrapericardial space.
For patients with pericarditis, fluid raises the pericardial sac away form the heart wall, thereby making puncture easier to achieve. However, for the patients with a normal pericardial sac and no extra fluid between the pericardial sac and the heart wall, gaining access into the intrapericardial space is difficult. This difficultly arises because: the normal pericardial sac is a thin tough connective tissue with little stretchability; the pericardial sac is slippery on, and slides over, the heart wall; and the “virtual space” that is available for puncture provides doctors with little puncture room for pressing the needle into the pericardial sac. “Virtual space” is the potential space between the two extreme limits of the epicardial surface and the pericardial sac.
The challenges of accessing an intrapericardial space of a healthy pericardium can easily result in the heart wall being punctured. While the thicker wall of the left vertical may seal up after puncture with a 17-gauge Touhy needle, punctures of the thin walled right ventricle, right atrium and left atrium will not easily seal, thereby increasing the risk for tamponade. Even if a heart wall puncture in the left ventricle is likely to seal, it is still difficult and frustrating to attempt to access the intrapericardial space, which is a virtual space in a patient with a healthy pericardium.
There is a need in the art for an apparatus that will facilitate accessing the intrapericardial space while reducing the risk of puncturing the heart wall. There is also a need in the art for a method of accessing the intrapericardial space that reduces the risk of puncturing the heart wall.